화학물질 노출 근로자를 위한 호흡보호구 선정 지침 개발

한돈희 ( Don Hee Han ),유계묵 ( Kye Mook Yoo ) 한국산업위생학회 2014 한국산업보건학회지 Vol.24 No.3

Objectives: Korean Occupational Safety and Health Agency (KOSHA) intended to provide guidance to respirator program administrators on respirator selection. The purpose of this project is to suggest a preliminary respirator selection guide (PRSG) for the final guidance certified by KOSHA for the correct selection of respirators in the workplace. Materials: This PRSG was made on the based of current status of respirator usage including respirators available in Korea, foreign documents search and so on. PRSG was partially modified NIOSH pocket guide to chemical hazards, 3M Respirator Protection Resource Guide (RPRG) and OSHA Assigned Protection Factor (APF) rulemaking. Results: Respirators for chemicals having Korean Occupational Exposure Limits (KOELs) can be recommended in PRSG. For the others chemicals that have no KOELs, PRSG tells you what respirators you can select, using a simple step-by-step approach after health hazard assessment like HSE procedure. Conclusions: PRSG helps you to decide the right level of protection for a given hazardous substance and how to select the right respirators. PRSG is thus expected to reduce significant misuses of respirators for the work environment.

보건관리자의 호흡보호구 관련 직무특성과 직무만족이 호흡보호구 인식도에 미치는 영향

정미경,어원석,김병직,이진희 (사)한국직업건강간호협회 2024 직업건강연구 Vol.6 No.1

Purpose : The purpose of this study is to investigate the impact of health managers' respirator-related job characteristics and job satisfaction on respirator recognition. Methods : The subjects of research and analysis were 203 health care managers working throughout the country, and the data were collected using Google forms from May 1, 2023 to May 10, 2023. The data analysis was performed using t-test, ANOVA, correlation analysis, and multiple regression analysis using SPSS/WIN 23.0. Results : Factors affecting the subject's recognition of respirators were job satisfaction(t=2.55, p=.012), participation in safety and health education instructors (t=-3.13, p=.002), and participation in selecting suitable protective equipment( t=2.49, p=.013), and suitablility for the respirator fit was tested(t=-1.34, p=.040)(F=5.10, p=<.001). Conclusion : In workplaces where respirators are used, it is necessary to support the legal work of health managers and increase job satisfaction, and efforts are needed to increase recognition of respirators. In addition, for workers' health management, respirator fit tests must be conducted to raise health managers' recognition of respirators and create a safety and health environment at the workplace.

Workplace Field Testing of the Pressure Drop of Particulate Respirators Using Welding Fumes

( Hyun Woo Cho ),( Chung Sik Yoon ) 대한보건협회 2011 대한보건협회 보건종합학술대회 Vol.2011 No.-

[Background] In a previous study, we concluded that respirator testing with a sodium chloride (NaCl) aerosol gave a conservative estimate of filter penetration for welding fume aerosols. A rapid increase in the pressure drop (PD) of some respirators was observed as fumes accumulated on the filters. [Purpose] The present study evaluated particulate respirator pressure drop (PD) based on workplace field tests. [Method] A field PD tester was designed and validated using the TSI 8130 Automatic Filter Tester, designed in compliance with NIOSH regulation 42 CFR part 84. Three models(two replaceable dual-type filters, one replaceable single-type filter) were evaluated against CO2 gas arc welding on mild steel. The mass concentration was measured by the gravimetric method, and number concentration was monitored using P-Trak (Model 8525, TSI, USA). Additionally, photos and scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDS) were used [Results] The field PD tester showed no significant difference compared with the TSI tester. There was no significant difference in the initial PD between lab and field results. The PD increased as a function of time and fume load on the respirator filters for all tested models. The increasing PD trend differed by models, and PD increased rapidly at high concentrations because greater amount of fumes accumulated on the filters in a given time. The increase in PD as a function of fume load on the filters showed a similar pattern as fume load varied for a particular model, but different patterns were observed for different models. Images and elemental analyses of fumes trapped on the respirator filters showed that most welding fumes were trapped within the second layer, first layer, and third layer, in order, while no fumes were observed beneath the fourth layer of the tested respirators. The current findings contribute substantially to our understanding of respirator PD in the presence of welding fumes.

방진마스크의 에어졸 방어효과와 밀착정도

한돈희 한국환경보건학회 2001 한국환경보건학회지 Vol.27 No.2

This review begins with a brief expression of aerosol capture mechanism of fibrous filter(s) and performance of particulate removing respirators. The more complicated and detailed discussion is not included in this articles. Filtration efficiency and pressure drop are introduced as quality factor ( $q_{F}$) and the way in which filtration efficiency varies with particle size is discussed. Quality factors fro filters recently certified in USA were found to be very higher than those of filters made in Korea, China and USA filters certified with old certified standards. Electrically charged filters are widely used because they have high filtration efficiency and low pressure drop, but their efficiency decreases sharply at the condition occurring wet and oil mist. A discussion is given of respirator leakage through face seal and filter media with fit testing and total inward leakage testing. Since fit factor (FF) refers to the reciprocal of the fraction of the total air entering a respirator through face seal leakage , the degree of fitting performance for respirators is expected with FF. Because respirators made in Korea had generally lower FFs than respirators made in USA, it is necessary to develope respirators that fit properly for Koreans or establish regulations for fit testing.g.

A Study on the Measurement of Respiratory Rate Using a Respirator Equipped with an Air Pressure Sensor

신우창 한국인터넷방송통신학회 2022 International journal of advanced smart convergenc Vol.11 No.4

In order to measure the respiratory rate, one of the major vital signs, many devices have been developed and related studies have been conducted. In particular, as the number of wearers of respirators increases in the COVID-19 pandemic situation, studies have been conducted to measure the respiratory rate of the wearer by attaching an electronic sensor to the respirator, but most of them are cases in which an air flow sensor or a microphone sensor is used. In this study, we design and develop a system that measures the respiratory rate of the wearer using an air pressure sensor in a respirator. Air pressure sensors are inexpensive and consume less power than the other sensors. In addition, since the amount of data required for calculation is small and the algorithm is simple, it is suitable for small-scale and low-power processing devices such as Arduino. We developed an algorithm to measure the respiratory rate of a respirator wearer by analysing air pressure change patterns. In addition, variables that can affect air pressure changes were selected, and experimental scenarios were designed according to the variables. According to the designed scenario, we collected air pressure data while the respirator wearer was breathing. The performance of the developed system was evaluated using the collected data.

Evaluation of a New Workplace Protection Factor―Measuring Method for Filtering Facepiece Respirator

Sun, Chenchen,Thelen, Christoph,Sanz, Iris Sancho,Wittmann, Andreas Occupational Safety and Health Research Institute 2020 Safety and health at work Vol.11 No.1

Background: This study aims to assess whether the TSI PortaCount (Model 8020) is a measuring instrument comparable with the flame photometer. This would provide an indication for the suitability of the PortaCount for determining the workplace protection factor for particulate filtering facepiece respirators. Methods: The PortaCount (with and without the N95-Companion^TM) was compared with a stationary flame photometer from Moores (Wallisdown) Ltd (Type 1100), which is a measuring instrument used in the procedure for determining the total inward leakage of the particulate filtering facepiece respirator in the European Standard. Penetration levels of sodium chloride aerosol through sample respirators of two brands (A and B) were determined by the two measuring systems under laboratory conditions. For each brand, thirty-six measurements were conducted. The samples were split into groups according to their protection level, conditioning before testing, and aerosol concentration. The relationship between the gauged data from two measuring systems was determined. In addition, the particle size distribution inside the respirator and outside the respirator was documented. Linear regression analysis was used to calculate the association between the PortaCount (with and without the N95-Companion^TM) and the flame photometer. Results: A linear relationship was found between the raw data scaled with the PortaCount (without N95-Companion^TM) and the data detected by the flame photometer (R² = 0.9704) under all test conditions. The distribution of particle size was found to be the same inside and outside the respirator in almost all cases. Conclusion: Based on the obtained data, the PortaCount may be applicable for the determination of workplace protection factor.

호흡보호구 디자인을 위한 삼차원 얼굴인식 및 측정에 관한 고찰

김현욱,김강윤 한국산업위생학회 2001 한국산업보건학회지 Vol.11 No.2

This article reviewed studies on the 3D face recognition and anthropometric facial analysis to design suitable respirators for individuals. 3D facial antoropometric data have not been reported in Korea yet. With 3D facial data, it is possible to design and to manufacture respirators having more effective respirator-face seal and thus providing more comfortable wearing than donning of those respirators designed using 1 and 2-dimensional data. Also 3D data could be used for respirator fit-testing and selecting suitable respirator type and size by computer simulation with out several steps of fit-test to each individual worker.

고압 적용용 초소형 감압기 설계를 위한 유동 해석 및 최적 설계

이원준(WonJun Lee),백종태(JongTae Baek),윤린(Rin Yun) 대한기계학회 2017 大韓機械學會論文集B Vol.41 No.8

산소호흡기의 실질적인 개발, 제작 및 안정성 파악을 위해서는 산소유동의 이론적인 연구가 필요하다. 이에 본 연구에서는 상용 해석 툴인 COMSOL 멀티피직스를 이용하여 산소호흡기의 사용시간 연장을 위한 고압용 감압기 설계를 진행하였다. 기존 감압기의 오리피스 내 핀 형태의 실린더 삽입 방법을 제안했으며, 새로 제시한 오리피스에 대해 3 mm, 6 mm 그리고 9 mm의 길이에서 유동 특성 분석 및 최적 길이를 도출하였다. 기존 감압기에서 토출되는 질량유량 0.028 kg/s을 기준으로, 최대 감압기 입구 압력인 300 bar 경우 약 33 %, 감압기 입구 압력조건인 50 bar, 75 bar 그리고 100 bar에서는 평균 32.71 % 내외로 기존 질량조건을 만족하였다. 가공 용이성을 고려할 때 기존의 감압기와 길이가 동일하여 별도의 가공이 필요 없는 3 mm가 가장 적합하다고 판단된다. A theoretical study on oxygen flow is fundamental to comprehend the practical production of an oxygen respirator and its stability. In this study, an orifice-type pressure-reducing component was designed for the newly developed oxygen respirator, using the commercial CFD tool, COMSOL Multiphysics, which increases its operational time compared to the existing component. The orifice was optimized by changing the length by 3, 6, and 9 mm within the entire computational domain of the oxygen respirator. Based on an oxygen flow rate of 0.028 kg/s, the oxygen respirator equipped with the newly developed orifice satisfied the flow rate within 33% for a respirator inlet pressure of 300 bar, and within 32.7% for 50, 75, and 100 bar. In terms of component manufacturing, the orifice length was selected as 3 mm, which removes additional changes to the existing component.

A Study on a Method for Detecting Leak Holes in Respirators Using IoT Sensors

신우창 한국인터넷방송통신학회 2023 International journal of advanced smart convergenc Vol.12 No.4

The importance of wearing respiratory protective equipment has been highlighted even more during the COVID-19 pandemic. Even if the suitability of respiratory protection has been confirmed through testing in a laboratory environment, there remains the potential for leakage points in the respirators due to improper application by the wearer, damage to the equipment, or sudden movements in real working conditions. In this paper, we propose a method to detect the occurrence of leak holes by measuring the pressure changes inside the mask according to the wearer's breathing activity by attaching an IoT sensor to a full-face respirator. We designed 9 experimental scenarios by adjusting the degree of leak holes of the respirator and the breathing cycle time, and acquired respiratory data for the wearer of the respirator accordingly. Additionally, we analyzed the respiratory data to identify the duration and pressure change range for each breath, utilizing this data to train a neural network model for detecting leak holes in the respirator. The experimental results applying the developed neural network model showed a sensitivity of 100%, specificity of 94.29%, and accuracy of 97.53%. We conclude that the effective detection of leak holes can be achieved by incorporating affordable, small-sized IoT sensors into respiratory protective equipment.

Microorganism-ionizing respirator with reduced breathing resistance suitable for removing airborne bacteria

Park, Miri,Son, Ahjeong,Chua, Beelee Elsevier 2018 Sensors and actuators. B, Chemical Vol.276 No.-

<P><B>Abstract</B></P> <P>In this paper, we have demonstrated the feasibility of using microorganism-ionizing respirators with reduced breathing resistance to remove airborne bacteria. Using a miniaturized corona ionizer and two pairs of separator electrodes, airborne bacteria were ionized and removed from the airflow. Two microorganism-ionizing respirator designs were experimentally evaluated with flow rates ranging from ∼10 to 20 L/min and yielded airborne bacterial removal efficiencies of ∼75%–100%. Further, they were in close agreement with the analytical airborne particle removal efficiencies, at a similar range of flow rates. These flow rates also correspond to the breathing rates of standing and walking adults. More importantly, the breathing resistance could be reduced by more than 50% for flow rates of ∼200 L/min. Using manganese (IV) oxide coated mesh, the ozone concentration in the air outflow was reduced to less than 0.1 ppm, at a flow rate of ∼20 L/min, thus enabling safe use. The power consumption was less than 1 W.</P> <P><B>Highlights</B></P> <P> <UL> <LI> We demonstrated the ability of microorganisms ionizing respirator to remove airborne bacteria. </LI> <LI> It uses miniaturized corona ionizer and separator electrodes. </LI> <LI> Airborne bacteria was electrically charged and removed from air flow. </LI> <LI> Its breathing resistance was less than that of commercial N95 respirator. </LI> <LI> Contributes to the comfort and ease of breathing of the wearer. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>